An electric power converter installed in an electric vehicle or a hybrid vehicle, etc. has a semiconductor module, a cooler, a circuit board, and a capacitor, for example.
The semiconductor module has a semiconductor element therein, while the cooler cools the semiconductor module.
A semiconductor control circuit that controls the semiconductor module is provided on the circuit board, while the capacitor is electrically connected to the semiconductor module.
In the electric power converter, a discharge resistor for discharging an electric charge accumulated in the capacitor is connected in parallel to the capacitor (refer to Japanese Patent Application Laid-Open Publication No. 2011-210026, for example).
By this, it is constituted that the electric charge of the capacitor can be discharged through the discharge resistor when an engine has stopped, etc.
However, quick discharging of the electric charge accumulated in the capacitor of the electric power converter is called for in recent years in emergency situations such as a collision of vehicles or other unusual detections, etc.
However, since a resistance value of the discharge resistor is configured larger from a viewpoint of preventing electric power loss during a regular operation, it is difficult to discharge the electric charge quickly through the discharge resistor.
Then, for the electric discharge in emergencies, it is considered that a quick discharge resistor with comparatively small resistance value should be connected to the capacitor while a current that flows into the quick discharge resistor is controlled by a discharge control circuit.
Thereby, it can be constituted that the discharge control circuit can permit the electric discharge using the quick discharge resistor in emergency situations, and the electric charge accumulated in the capacitor may be discharged in a short time.
However, providing the quick discharge resistor and the discharge control circuit in the electric power converter has a possibility of causing the following problems.
That is, if a circuit board is prepared anew in order to provide the discharge control circuit, an increase in a number of parts, enlargement of the body, and an increase in assembling man-hours will be caused in the electric power converter.
Moreover, depending on a spatial relationship of the quick discharge resistor and the circuit board in which the discharge control circuit is provided and other component parts, there is a possibility that a connecting means between the parts including the circuit board may become complicated, and assembling man-hours may increase.